1. Field of the Invention
The present invention relates generally to a mobile electronic equipment such as a portable computer called a palmtop or a laptop or a notebook computer, or a portable terminal called a PDA (Personal Digital Assistant), and more particularly, to an internal antenna structure for such mobile electronic equipment and to mobile electronic equipment incorporating the antenna.
2. Description of the Background Art
A mobile electronic equipment is operated by power supplied from a compact portable battery and types of such devices include a portable terminal such as a PDA, a palmtop computer or a laptop computer or a notebook computer.
Research has been ongoing to make the mobile electronic equipment more compact and lighter-weight and to have a multifunctional capacity, and also for making it possible to radio-frequency communicate by radio with an external instrument.
Especially, there have been introduced data communication devices which transmit or receive data wirelessly between a desktop computer or a server, or to enable a LAN card or a modem card inserted in a main body and an external instrument to communicate with each other wirelessly without using a connecting cable to access a network.
In order to adopt the radio communication to the mobile electronic equipment, it is requisite to adopt a high efficiency antenna. But, notably, there are inconvenient aspects and restrictions in designing such an antenna and in its adaptation to the mobile electronic equipment due to the special requirement that it should be mounted for use in a compact mobile electronic equipment.
For one example, a conventional antenna structure has been proposed in which a pull-up type rod antenna is mounted within a main body of the mobile electronic equipment and pulled out therefrom for use in a radio communication.
Such antenna, however, has a problem that since a rod of the antenna remains exposed outside the main body, designing of the outer case is not easy and an elegant appearance would be hardly accomplished, and furthermore a space is required to install the antenna therein, resulting in that the size of the product is increased.
For another example, U.S. Pat. No. 6,181,284 entitled ‘antenna for portable computer’ by Madsen et al. discloses an antenna which is installed to be bent at one upper side of a main body of a computer. In this patent, the antenna is received in a storage portion formed in the vicinity of the antenna when the computer is not in a use, while when the computer is desired to be used, a display case of the computer is stood upright and the antenna is stood vertically from the storage portion for communicating.
However, because the antenna of Madsen et al. protrudes vertically from the case when in use, there is a risk that it can be damaged due to a user's inadvertence.
For still another example, U.S. Pat. No. 5,684,672 entitled ‘Laptop computer with an integrated multi-mode antenna’ by Karidis et al. discloses a multi-mode type whip antenna installed at one inner side of a display case of a computer.
However, the antenna of Karidis et al. has such a construction that it is withdrawn to be extended from the display case for the purpose of obtaining the maximum efficiency when it is in use, while it is drawn back for a firmness and convenience when it is not in use. Thus, when the antenna is withdrawn for use, it could be caught by a person or other objects and damaged.
To sum up, the portable computer, a kind of mobile electronic equipment, according to the conventional art has the following problems.
That is, those antennas are constructed to be exposed outwardly of the computer main body or the case when it is in use. Thus, when a user desired to use the antenna for a radio communication, he or she must directly operate the antenna to be exposed. In addition, while the user is using the computer with the antenna exposed, there is a high risk that the antenna could be damaged.